Using a task-based approach in evaluating the usability of BoBIs in an e-book environment

This paper reports on a usability evaluation of BoBIs (Back-of-the-book Indexes) as searching and browsing tools in an e-book environment. This study employed a task-based approach and within-subject design. The retrieval performance of a BoBI was compared with a ToC and Full-Text Search tool in terms of their respective effectiveness and efficiency for finding information in e-books. The results demonstrated that a BoBI was significantly more efficient (faster) and useful compared to a ToC or Full-Text Search tool for finding information in an e-book environment

Probing dissipation mechanisms in BL Lac jets through X-ray polarimetry

The dissipation of energy flux in blazar jets plays a key role in the acceleration of relativistic particles. Two possibilities are commonly considered for the dissipation processes, magnetic reconnection -- possibly triggered by instabilities in magnetically-dominated jets -- , or shocks -- for weakly magnetized flows. We consider the polarimetric features expected for the two scenarios analyzing the results of state-of-the-art simulations. For the magnetic reconnection scenario we conclude, using results from global relativistic MHD simulations, that the emission likely occurs in turbulent regions with unstructured magnetic fields, although the simulations do not allow us to draw firm conclusions. On the other hand, with local particle-in-cell simulations we show that, for shocks with a magnetic field geometry suitable for particle acceleration, the self-generated magnetic field at the shock front is predominantly orthogonal to the shock normal and becomes quasi-parallel downstream. Based on this result we develop a simplified model to calculate the frequency-dependent degree of polarization, assuming that high-energy particles are injected at the shock and cool downstream. We apply our results to HBLs, blazars with the maximum of their synchrotron output at UV-soft X-ray energies. While in the optical band the predicted degree of polarization is low, in the X-ray emission it can ideally reach 50\%, especially during active/flaring states. The comparison between measurements in the optical and in the X-ray band made during active states (feasible with the planned {\it IXPE} satellite) are expected to provide valuable constraints on the dissipation and acceleration processes.Comment: 9 pages, 6 figures, accepted for publication by MNRA

Volunteer Retention in Prosocial Venturing: The Role of Emotional Connectivity

This study develops an understanding of the role of emotional connectivity for volunteer retention in prosocial business venturing. By embedding it in organizational ambivalence theory, our analysis of four volunteer-dependent community ventures reveals two mechanisms through which entrepreneurs strengthen volunteers’ emotional connectivity. We first identify emotion-focused practices that form volunteers’ emotional attachment to the venture, and then demonstrate how duality-focused practices, in the form of managing inherent organizational duality, complement emotion-focused practices to foster volunteers’ emotional loyalty to the venture. Theorizing from our findings, we introduce a model of managing volunteers’ emotional connectivity, and conclude by discussing its implications for prosocial venture research on volunteerism and affective commitment

Pharmacokinetics (PK), pharmacodynamics (PD), and PK-PD integration of danofloxacin in sheep biological fluids

The fluoroquinolone antimicrobial drug danofloxacin was administered to sheep intravenously (i.v.) and intramuscularly (i.m.) at a dose of 1.25 mg/kg of body weight in a two-period crossover study. The pharmacokinetic properties of danofloxacin in serum, inflamed tissue cage fluid (exudate), and noninflamed tissue cage fluid (transudate) were established by using a tissue cage model. The in vitro and ex vivo activities of danofloxacin in serum, exudate, and transudate against a pathogenic strain of Mannheimia haemolytica were established. Integration of in vivo pharmacokinetic data with the in vitro MIC provided mean values for the area under the curve (AUC)/MIC for serum, exudate, and transudate of 60.5, 85.6, and 45.7 h, respectively, after i.v. dosing and 55.9, 77.9, and 49.1 h, respectively, after i.m. dosing. After i.m. dosing, the maximum concentration/MIC ratios for serum, exudate, and transudate were 10.8, 3.0, and 1.6, respectively. The ex vivo growth inhibition data after i.m. dosing were fitted to the inhibitory sigmoid Emax equation to provide the values of AUC/MIC required to produce bacteriostasis, bactericidal activity, and elimination of bacteria. The respective values for serum were 17.8, 20.2, and 28.7 h, and slightly higher values were obtained for transudate and exudate. It is proposed that use of these data might provide a novel approach to the rational design of dosage schedules.Facultad de Ciencias Veterinaria

Probing shock acceleration in BL Lac jets through X-ray polarimetry: the time-dependent view

Polarimetric measurements, especially if extended at high energy, are expected to provide important insights into the mechanisms underlying the acceleration of relativistic particles in jets. In a previous work we have shown that the polarization of the synchrotron X-ray emission produced by highly energetic electrons accelerated by a mildly relativistic shock carries essential imprints of the geometry and the structure of the magnetic fields in the downstream region. Here we present the extension of our analysis to the non-stationary case, especially suitable to model the highly variable emission of high-energy emitting BL Lacs. We anticipate a large ($\Pi \approx 40\%$), almost time-independent degree of polarization in the hard/medium X-ray band, a prediction soon testable with the upcoming mission {\it IXPE}. The situation in other bands, in particular in the optical, is more complex. A monotonic decrease of the optical degree of polarization is observed during the development of a flare. At later stages $\Pi$ reaches zero and then it starts to increase, recovering large values at late times. The instant at which $\Pi=0$ is marked by a rotation of the polarization angle by $90$ degrees. However, at optical frequencies it is likely that more than one region contributes to the observed emission, potentially making it difficult to detect the predicted behavior.Comment: 11 pages, 9 figures, accepted for publication by MNRA

Money management and entrepreneurial training in microfinance: impact on beneficiaries and institutions

This study uses a randomized control trial to evaluate the outcome of integrating money management and entrepreneurial training into a microcredit program in India. We find positive and significant effects on clients\u2019 financial management skills and entrepreneurship abilities, particularly for clients with higher human capital, or more diligent, or having an entrepreneurial idea, and an increase in initiative and self-confidence. Effects appear stronger for clients obliged to attend the training course or more interested in attending it. By considering missed or delayed repayments reduction we assess the benefits of the training provided and of extending it for the institution

The circum-galactic medium of quasars: CIV absorption systems

We investigate the properties of the circumgalactic gas in the halo of quasar host galaxies from CIV absorption line systems. Optical spectroscopy of closely aligned pairs of quasars (projected distance \leq 200 kpc) obtained at the Gran Telescopio Canarias is used to investigate the distribution of the absorbing gas for a sample of 18 quasars at z \sim 2. We found that the detected absorption systems of EW \geq 0.3Ang associated with the foreground QSO are revealed up to 200 kpc from the center of the host galaxy. The structure of the absorbing gas is rather patchy with a covering fraction of the gas that quickly decreases beyond 100 kpc. These results are in qualitative agreement with those found for the lower ionisation metal Mg II 2800 Ang.Comment: Very minor revision . Accepted for publication in MNRA